Atomic disorder, a widespread problem in compound crystalline materials, is a imperative affecting the performance of multi-chalcogenide Cu2ZnSn(S, Se)4 (CZTSSe) photovoltaic device known for its low cost and environmental friendliness. Cu-Zn disorder is particularly abundantly present in CZTSSe due to its extraordinarily low formation energy, having induced high-concentration deep defects and severe charge loss, while its regulation remains challenging due to the contradiction between disorder-order phase transition thermodynamics and atom-interchange kinetics. Herein, through introducing more vacancies in the CZTSSe surface, we explored a vacancy-assisted strategy to reduce the atom-interchange barrier limit to facilitate the Cu-Zn ordering kinetic process. The improvement in the Cu-Zn order degree has significantly reduced the charge loss in the device and helped us realize 15.4% (certified at 14.9%) and 13.5% efficiency (certified at 13.3%) in 0.27 cm2 and 1.1 cm2-area CZTSSe solar cells, respectively, thus bringing substantial advancement for emerging inorganic thin-film photovoltaics.
@article{arxiv.2404.05974,
title = {Vacancy enhanced cation ordering enables >15% efficiency in Kesterite solar cells},
author = {Jinlin Wang and Licheng Lou and Kang Yin and Fanqi Meng and Xiao Xu and Menghan Jiao and Bowen Zhang and Jiangjian Shi and Huijue Wu and Yanhong Luo and Dongmei Li and Qingbo Meng},
journal= {arXiv preprint arXiv:2404.05974},
year = {2024}
}